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  1. redwire

    0-30V Stabilized Power Supply

    PicMaster,  How come R1 and R2 in your sketch  have signifcantly different values than the revised parts list?
  2. redwire

    0-30V Stabilized Power Supply

    When you asked me earlier about P3,  I thought you were referring to point 3 from the original sketch instead of Potentiometer 3.  I don't think I ever labeled it P3, so it was throwing me off.    I don't have the coarse and fine Potentiometers shown on the Eagle PCB file I posted because no...
  3. redwire

    0-30V Stabilized Power Supply

    hint:  look for a "3" near the top of the pcb
  4. redwire

    0-30V Stabilized Power Supply

    effenberg0x0 I home built my transformer from a microwave oven transformer.   I cut the windings and rewound it using copper tape.   My max voltage output is 58V unloaded.   I don't know the rated capacity is but I've held it at 7 amps for a short period, cut it off and check the transformer...
  5. redwire

    0-30V Stabilized Power Supply

    I used a 0R27 10W cement resistor not just because I wanted a 5A version but to also reduce wasted power.   The 10w version is longer than the 5W resistor so it dissipates heat better.  Although you can not see it on the first post of this thread, the cement resistor is not sitting on the board...
  6. redwire

    0-30V Stabilized Power Supply

    effenberg wrote: Why don't you build the non SMD version that is linked to the above site. Original design page located here: http://elfly.pl/multimetr/multimetr_en.htm Yes,  several have built is successfully.  I have a non smd LCD version working on mine.    I'll post some pictures later.
  7. redwire

    0-30V Stabilized Power Supply

    corsa,  That looks correct.    If you notice a few extra holes or pins it's because I added a few to connect the LCD display and one led connection for your front ase.  It will work with or without the pins installed.
  8. redwire

    0-30V Stabilized Power Supply

    corsa     The area contained  in the blue shape on the left hand side of the pcb should all be a solid blue ground plane.    I used an earlier version of EAGLE  to create the pcb and I had to down load the latest version to open your copy.   You need to take the original version I posted,  and...
  9. redwire

    0-30V Stabilized Power Supply

    Hi effenberg0x0.              There are insignificant differences between audioguru's part list and mine.  Mine reflect preferences rather than errors.  I wanted to have a little more range so I used a 0.27ohm power resister instead of the 0.49 ohm in the original.  Some of the calibration...
  10. redwire

    0-30V Stabilized Power Supply

    Hi karthikeid    I posted my pcb file a few pages up but here is the link:     http://www.electronics-lab.com/forum/index.php?topic=19066.msg89170#msg89170
  11. redwire

    0-30V Stabilized Power Supply

    Corsa,  you may be able to use the Eagle file I posted to change the double sided pcb to a single sided board.  This may require some jumper wires.    Note that some of the traces are quite wide to handle large currents.  Most are not.    If you don't want to create your own pcb send me a PM.
  12. redwire

    0-30V Stabilized Power Supply

    Hi Corsa,   Here is the pcb in EAGLE for the board at the top of the thread.  It is a double sided board because I had it produced at a professional shop.   It is somewhat of a challenge to build double sided boards at home. Note that D2 and D3 need to be filled with a 1N4148 and D7 is not used...
  13. redwire

    0-30V Stabilized Power Supply

    Zsyt may be able to use the transformer with the revised design posted at the beginning of the thread.  RV3 is used to regulate the max output to stay within the parameters of the transformer and board.
  14. redwire

    0-30V Stabilized Power Supply

    Yes, it goes with the sketch you posted.    For the 5A version I would recommend the following: 1.    30VAC  7.2A  or higher  stepdown transformer 2.    R7 = 0.27, 10W resistor 3.    C1= 20,000 uf, 63V 4.    Q4, Q5 & Q6  (at least 3 paralleled ) NPN transistors on huge heatsinks. Actually...
  15. redwire

    0-30V Stabilized Power Supply

    Here is the latest  parts list I have.  Not sure if it matches Audioguru's list,  but if it doesn't that's what this forum is all about. PS_Parts_List_10-11-09.pdf
  16. redwire

    0-30V Stabilized Power Supply

    Thanks,  Now we have a sketch and some parts.  We can continue the discussion.
  17. redwire

    0-30V Stabilized Power Supply

    Audioguru,  do you have a copy of the last parts list using the alternate chips.  I seem to remember some of revisions were in red. EDIT:  The first post contains REV 5 in the zip file.  Audioguru's post directly above this also contains the same update.  No need to read the next 125 pages...
  18. redwire

    0-30V Stabilized Power Supply

    We seem to have lost the extensive discussion on this power supply topic.    I attached what I believe is the latest version.   NOTE the parts list included in the attached zip file is REV 5 dated 12/13/13  and  covers the next 125 pages of this tread.      0-30V.zip
  19. redwire

    0-30 Vdc Stabilized Power Supply

    Hi, Josko,  you may want to be cautious about using a pcb designed for 3-5 amps and try to pump 12A through it.  Although most of the components will only experience ma's, a few tracing will need to supply the full 12 A.  Make sure they are wide enough.  Also your main cap will need to be...
  20. redwire

    0-30 Vdc Stabilized Power Supply

    rcakto    For the large cap you have lots of options to use,  one, two  or parallel several.  On one build I used 3  of these  661-EKMH630VNN562MR (mouser part #)    It doesn't need to be exactly 12,000uf.
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